Determination of magnesium element content in aluminum alloy is an essential means for quality control in enterprises which produce magnesium-containing aluminum alloys. Besides instrumental analytic methods (e.g., atomic absorption spectrometry, ICP-AES method), high content of magnesium in aluminum alloy usually is determined by EDTA complexometric titration methods, currently including two major well-developed methods: copper-reagent method and potassium cyanide method. The copper-reagent method comprises two filtering separation steps resulting in complicated operation and prolonged analytical period and thus is not suitable for on-the-spot sample analysis. The potassium cyanide method is simple and rapid, conventionally used as an on-the-spot analysis method in aluminum processing factories.
Potassium cyanide is an excellent masking agent, but also a high toxic agent harmful to human beings and environment. Hence, there still is a need to find a substitute of potassium cyanide to realize a rapid cyanide-free determination of magnesium content.